Some swimming pool pump systems are designed with a single speed pump, which typically produces a given output at a given pressure. With these systems, ancillary equipment is operated by the filter pump at the given output and pressure. The ancillary equipment may include pool cleaners, chlorinators, and chemical feeders. In order to reduce electrical use requirements of the swimming pool pump system, variable and multi-speed pumps are used as an alternative to single speed pumps. When variable speed pumps are run on slow speed, the pressure/output (measured as GPM) is typically not sufficient to properly operate the attached equipment. Furthermore, the equipment is often damaged due to incorrect operating pressures/outputs. This condition is especially problematic when a variable speed pump is used to replace a single speed pump on existing installations.
Moreover, typical pool pump systems connect electrically operated ancillary equipment in parallel to the pump motor in order to operate the ancillary equipment in unison with the pool pump. Many variable speed motors are internally solid state controlled. The electrical connection to these motors is always “hot” or on, making the former electrical connection unworkable.